pmc.ncbi.nlm.nih.gov

Advanced training in trauma life support for ambulance crews

Abstract

Background

There is an increasing global burden of injury especially in low‐ and middle‐income countries (LMICs). To address this, models of trauma care initially developed in high income countries are being adopted in LMIC settings. In particular, ambulance crews with advanced life support (ALS) training are being promoted in LMICs as a strategy for improving outcomes for victims of trauma. However, there is controversy as to the effectiveness of this health service intervention and the evidence has yet to be rigorously appraised.

Objectives

To quantify the impact of ALS‐trained ambulance crews versus crews without ALS training on reducing mortality and morbidity in trauma patients.

Search methods

The search for studies was run on the 16th May 2014. We searched the Cochrane Injuries Group's Specialised Register, the Cochrane Central Register of Controlled Trials (CENTRAL, The Cochrane Library), Ovid MEDLINE(R), Ovid MEDLINE(R) In‐Process & Other Non‐Indexed Citations, Ovid MEDLINE(R) Daily and Ovid OLDMEDLINE(R), Embase Classic+Embase (Ovid), ISI WOS (SCI‐EXPANDED, SSCI, CPCI‐S & CPSI‐SSH), CINAHL Plus (EBSCO), PubMed and screened reference lists.

Selection criteria

Randomised controlled trials, controlled trials and non‐randomised studies, including before‐and‐after studies and interrupted time series studies, comparing the impact of ALS‐trained ambulance crews versus crews without ALS training on the reduction of mortality and morbidity in trauma patients.

Data collection and analysis

Two review authors assessed study reports against the inclusion criteria, and extracted data.

Main results

We found one controlled before‐and‐after trial, one uncontrolled before‐and‐after study, and one randomised controlled trial that met the inclusion criteria. None demonstrated evidence to support ALS training for pre‐hospital personnel. In the uncontrolled before‐and‐after study, 'a priori' sub‐group analysis showed an increase in mortality among patients who had a Glasgow Coma Scale score of less than nine and received care from ALS trained ambulance crews. Additionally, when the pre‐hospital trauma score was taken into account in logistic regression analysis, mortality in the patients receiving care from ALS trained crews increased significantly.

Authors' conclusions

At this time, the evidence indicates that there is no benefit of advanced life support training for ambulance crews on patient outcomes.

Plain language summary

Advanced training in trauma life support for ambulance crews

Injury is one of the top ten causes of death and disability worldwide. It results in an early loss of life for many young people and ongoing high medical care costs among survivors. Advanced life support (ALS) training for ambulance crews with emphasis on trauma is believed to have contributed to a reduction in the number of deaths from injury in predominantly high‐income countries where this service is available. ALS services are also being adapted for low‐ and middle‐income countries. This review of trials found there is no evidence to suggest that ALS training for ambulance personnel improves the outcomes for injured people.

Background

The epidemiological, demographic, and socio‐political transitions underway in many countries are associated with an increasing burden of disease from injury, particularly in low‐ and middle‐income countries (LMICs). These findings have been highlighted by the Global Burden of Disease Study, which identified injury as one of the top ten causes of death and disability worldwide (Murray 1997a; Murray 1997b; Murray 1997c; Lopez 2006). That study also predicted that the incidence of injury was likely to increase by the year 2030 (Mathers 2006). Although infectious diseases are still extremely important causes of death in LMICs, the challenges of injury and non‐communicable disease add to these as important causes of premature mortality and morbidity (Gwatkin 1997). Injuries place a disproportionately large burden of disease on young people (Murray 1997a; Murray 1997b), and, consequently, are a leading cause of premature loss of productive life, of high medical care costs, of significant degrees of disability and of large socio‐economic loss to society (Berger 1996).

There have been recent calls by the public health community and civil organisations to formulate a strategy to decrease the burden from injuries. While responding to injuries requires considerable attention to preventive efforts (Berger 1996), improvements in health care provision which reduce deaths, disability and societal costs are also required (Sethi 2000). In many high income countries (HICs), reductions in trauma mortality of 15% to 20% have been achieved in the last few decades (Cales 1984; Roberts 1996; Lecky 2000), which may be partly as a result of improved systems for trauma care. Advanced life support (ALS) training for ambulance personnel is considered to have made an important contribution to the reduction of trauma mortality in HIC settings (Kirsch 1998; Reines 1998). ALS‐trained ambulance crews receive extra training in endotracheal intubation, intravenous cannulation, the administration of intravenous fluids, and the use of selected drugs (Calicott 1980). In high‐income countries a substantial proportion of ambulance crews now include an ALS‐trained officer. For example, in the UK, Department of Health policy requires that all emergency ambulances include an ambulance officer trained in ALS (AACE 2013; DoH 2011; JRCALC 2010).

In response to the increasing global burden of injury, LMICs are rapidly adopting models of trauma care initially developed in high‐income countries, such as ALS training for ambulance crews to improve outcomes in injury victims (Ali 1993; Sethi 2000). In many LMICs, the majority of patients arrive by private transport, although many countries have been developing pre‐hospital care services further (Hauswald 1997; Areola‐Risa 2000). As LMICs consider various models of pre‐hospital care, the use of ALS training for ambulance crews has been debated (Sklar 1988; VanRooyen 1999). Little systematic evaluation of existing evidence is available for such policy‐making.

Why it is important to do this review

The evidence for the impact of ALS‐trained ambulance crews has yet to be rigorously appraised. The aim of this systematic review is therefore to quantify the impact of ambulance crews with ALS training on outcomes following trauma.

Objectives

To quantify the effects of ALS‐trained ambulance crews versus crews without ALS training on reducing mortality and morbidity in injured patients.

Methods

Criteria for considering studies for this review

Types of studies

Randomised controlled trials (RCTs), controlled trials (CTs), before‐and‐after (CBAs, BAs) and interrupted time series (ITSs) studies.

Types of participants

All adult trauma patients over 18 years.

Types of interventions

ALS‐trained ambulance crews with specific trauma training (including ATLS or PHTLS or other equivalent) versus crews without ALS training.

Types of outcome measures

  • Death from all causes at the end of the follow‐up period scheduled for each study

  • Morbidity

Search methods for identification of studies

In order to reduce publication and retrieval bias we did not restrict our search by language, date or publication status.

Electronic searches

The Cochrane Injuries Group's Trials Search Co‐ordinator searched the following:

  1. Cochrane Injuries Group Specialised Register (16th May 2014);

  2. Cochrane Central Register of Controlled Trials (CENTRAL, The Cochrane Library) (issue 4 of 12, 2014);

  3. Ovid MEDLINE(R), Ovid MEDLINE(R) In‐Process & Other Non‐Indexed Citations, Ovid MEDLINE(R) Daily and Ovid OLDMEDLINE(R) 1946 to 16th May 2014;

  4. Embase Classic+Embase (OvidSP) 1947 to 16th May 2014;

  5. ISI Web of Science: Science Citation Index Expanded (SCI‐EXPANDED) (1970 to May 2014);

  6. ISI Web of Science: Conference Proceedings Citation Index ‐ Science (CPCI‐S) (1990 to May 2014);

  7. CINAHL Plus (EBSCO Host) 1937 to May 2014;

  8. PubMed (16th May 2014).

The search strategies are also used for the review 'Advanced trauma life support training for hospital staff' (Jayaraman 2014) and are given in Appendix 1.

Searching other resources

We screened the reference lists of all trial reports included in the review to identify any further published and unpublished data.

Data collection and analysis

Selection of studies

One review author (SJ) screened the search results and applied the inclusion criteria.

Data extraction and management

Two review authors (SJ and RW) extracted information on the following: study design, stratification for effect modifiers, method of allocation concealment, number of randomised patients, type of participants, and interventions and outcomes. The outcome data sought were mortality and morbidity. The review author was not blinded to the authors or journal when doing this, although evidence for the value of blinding the review authors is not conclusive (Berlin 1997).

Assessment of risk of bias in included studies

We assessed study quality using the recommendations outlined in chapter 8 of the Cochrane Handbook for Systematic Reviews of Interventions to determine the degree to which systematic bias may have been introduced, such as: bias through selection, performance, exclusion or detection; the method of allocation; the degree of follow‐up, and the soundness of the assessments. Two review authors (SJ and RW) categorised the studies as RCTs, CCTs, BAs and ITSs and applied these specific categories of quality assessment to the trial reports.

Assessment of heterogeneity

The groups of trials would have been examined for statistical evidence of heterogeneity using the Chi2 test. If there was no obvious heterogeneity on visual inspection or statistical testing, pooled relative risks and 95% confidence intervals would have been calculated using a fixed‐effect model.

Subgroup analysis and investigation of heterogeneity

The following comparisons were planned:

Mortality and morbidity of victims of trauma treated by ALS‐trained ambulance crews versus crews without ALS training. 'A priori' sub‐group analyses reported by studies were evaluated to look for statistically significant differences that were not apparent in the overall analyses.

The intended analysis was the calculation of relative risk of death and 95% confidence interval for each trial, such that a relative risk of more than one indicates a higher risk of death. We chose relative risk as it can be more readily applied to clinical situations.

Sensitivity analysis

The effect of excluding trials judged to be inadequate according to the Cochrane Handbook for Systematic Reviews of Interventions (Higgins 2011) criteria for quality would have been examined in a sensitivity analysis.

Results

Description of studies

Results of the search

The search covered all years to May 2014. The process of identifying new studies is given in Figure 1. Three studies are included in this review.

1.

1

Study flow diagram.

Included studies

Arreola‐Risa 2004 This was a controlled before‐and‐after study on mortality from injury in three Mexican cities (Monterrey, San Pedro and Santa Catarina). In San Pedro, ambulance staff received training in Basic Trauma Life Support (BTLS), Advanced Cardiac Life Support, and a locally designed airway course. In Monterrey, ambulance staff received training in pre‐hospital Trauma Life Support (a BTLS equivalent). In Santa Catarina, no additional training was provided (i.e. this was the control group). Before and after comparisons were made in Monterrey in 1994 and 1995, and in 2000 and 2001 for both San Pedro and Santa Catarina. Data were collected using self‐reported ambulance‐run sheets. The main treatment outcome was mortality from trauma. Secondary outcomes included effects of training on use of three specific skills and arrival time.

The number of trauma patients treated by ambulance personnel during the study period were 866 in Monterrey, 510 in San Pedro, and 504 in Santa Catarina. The injured patients were predominantly male and sustained mostly blunt injuries. In the follow‐up period, patients in Monterrey (BLS group) received statistically greater numbers of all procedures for the three key management areas: airway management, fluid resuscitation and spinal immobilisation whereas patients in San Pedro (ALS group) received better management in some areas but not all. Management of these three areas were unchanged in Santa Catarina (the control group). However, despite these improvements in process indicators in Monterrey and to a lesser extent in San Pedro, the study demonstrates no statistically significant change in mortality in any of the three settings. When deaths on scene were excluded, there was a small trend towards lower mortality among injured patients in Monterrey (BLS group) but not in the other two settings.

Nicholl 1998 This RCT compared outcomes of victims of trauma treated by ambulance crews with ALS training to outcomes of those treated by crews without ALS training. Participants were trauma (road traffic accidents, falls, work/chemical/sport accidents, self‐harm, assaults and drowning) patients of all ages. People with superficial injuries were excluded. Follow‐up was six months after the original incident and was performed using the SF‐36 questionnaire. Protocol compliance was poor. The authors did not recruit sufficient numbers because of practical difficulties. The mortality and morbidity data of the randomised group were added to the main non‐randomised cohort in the original analysis. Therefore, specific analysis of the randomised patients cannot be performed for this review.

Stiell 2008 This was a large scale uncontrolled before‐and‐after study which took place across 17 cities in Canada. The study addressed the impact of ALS training for the healthcare personnel who help patients before they reach hospital on patient mortality and morbidity due to injury. The study population included injured patients over 16 years of age with an injury severity score greater than 12. Participants were transported by land ambulance and were treated at one of the 13 leading trauma hospitals in Ontario province. Data on pre‐hospital care were collected from ambulance call reports and the provincial dispatch centre. Individual eligible patients with major trauma seen during the basic life‐support phase (36 months) and the advanced life‐support phase (36 months) were enrolled. The study intervention consisted of standardised national curriculum on advanced life‐support and clinical training period programs. A total of 400 paramedics were trained to perform endotracheal intubation, insert intravenous lines and administer medications and fluids intravenously. The primary outcome was survival to hospital discharge (alive or being transferred to a long‐term care facility) and was obtained from hospital records. Additionally, disease‐specific quality of life in survivors was measured with the 7‐level functional independence measure at discharge and six months. The sample size was determined assuming a minimum absolute difference in the primary outcome of 3.8% between study phases.

A total of 2867 patients were enrolled: 1373 in the BLS phase and 1494 in the ALS phase. There was no substantial difference in overall survival to hospital discharge by phase (81.8% for BLS versus 81.1% for ALS). The only exception to this finding was a lower survival in an 'a priori' sub‐group of cases with an initial Glasgow Coma Scale score of less than nine. This group had lower survival rates in the advanced life‐support phase than in the basic life‐support phase (60.1% versus 51.2%; P = 0.03). There were no differences in morbidity between the phases, as indicated by the Glasgow Outcome Scale and functional independence measure at discharge and six months after discharge. Based on the revised trauma score obtained from the trauma hospital, mortality was non‐significantly increased for patients in the ALS phase (adjusted odds ratio = 1.2), but when the pre‐hospital revised trauma score was used, mortality was worse in the intervention phase (adjusted odds ratio = 1.4, 95% CI 1.0 to 1.9). The presence of ALS providers at the scene and intubation in the field were associated with increased mortality (adjusted OR 1.5, 95% CI 1.1 to 2.0 and adjusted OR 2.8, 95% CI 1.6 to 5.0, respectively). However, total response time was statistically longer in the ALS group than in the BLS group. Univariate analysis revealed that non‐survivors were more likely to be intubated in the field than survivors, and intubations in the field were associated with increased odds of death in multivariate analysis. Based on this, ALS procedures were thought to lead to delays and longer response times which may explain why better trained paramedics have worse outcomes than others.

The characteristics of these studies are included in the Characteristics of included studies table.

Excluded studies

Nine studies were considered for inclusion in the review, but were ineligible as they did not fulfil the study design criteria. A short description of each study is given in the Characteristics of excluded studies table.

Risk of bias in included studies

Arreola‐Risa 2004: Limitations that may have biased the results include having only one control site, testing the intervention in only a few sites, difference in the time frame between groups, and a lack of sample size calculations to evaluate appropriate effect sizes. Because this was not a randomised controlled trial, allocation and blinding could not be done. Thus potential confounders may not have been adequately addressed.

Nicholl 1998: The dispatch of ambulance crews was randomised by opening a sealed, numbered envelope when a potential eligible emergency call was received by the dispatcher. Blinding of outcome assessments was not reported. The poor protocol compliance could have affected the results.

Stiell 2008: The most important limitation of this study was its design as an uncontrolled before‐and‐after study rather than a randomised trial, which is the gold standard to test such an intervention. The authors suggest that since randomised trials are challenging to conduct in the pre‐hospital setting for ethical reasons, the study design was, in this case, the optimal method of answering the study question. Furthermore, sub‐group analyses suggested higher mortality in patients with a lower Glasgow Coma Score although this may be a false positive finding and would need to be evaluated further.

Effects of interventions

All three studies included in this review demonstrated no reduction in mortality for injured patients receiving aid from ALS‐trained ambulance crews versus BLS‐trained crews. The only randomised controlled trial was too small to show the impact of ALS training on injury mortality and morbidity. There may be some evidence to suggest that such training negatively affects mortality in some groups. In Stiell 2008, an 'a priori' sub‐group analysis demonstrated an increase in mortality among patients in the intervention group who had a Glasgow Coma Score less than nine. Additionally, when the pre‐hospital trauma score was taken into account in logistic regression analysis, mortality in the patients receiving care from ALS trained crews increased significantly.

Discussion

Three studies met the inclusion criteria for this review. This is in spite of conducting a very thorough literature search in which a total of 4674 citations have been screened to identify eligible trials. We believe it is unlikely that relevant trials have been overlooked.

Based on the limited data, there is at present no evidence to recommend ALS training of ambulance crews to care for injury victims. This finding highlights the lack of evidence on which current practice and policy in many high‐income countries is based, where pre‐hospital care is often provided by ambulance crews with ALS training. It emphasizes the need to conduct well‐designed intervention studies to establish this effectiveness and inform policy making in trauma services.

The lack of rigorous research may not be easily rectified in settings where ALS‐based services have already been established. There is conviction among the public, the media, and health professionals (including ambulance service staff), that ALS interventions are beneficial in serious trauma. However, despite the practical problems that may be experienced during research, randomised controlled trials remain the most rigorous research design for evaluating health care interventions.

A number of other factors need to be taken into account in planning an evaluative and comparative investigation in pre‐hospital care of injury victims. These include the impact of ALS interventions on scene time, the impact of scene time on outcomes, the mechanism of trauma (blunt versus penetrating), geographical location (distance from hospital care), injury severity, injury pattern (presence and severity of head injury) and mode of pre‐hospital transport. In addition, the configuration of pre‐hospital services needs to be considered. For example, in some countries ambulances are staffed by doctors, many of whom have postgraduate or specialist training in intensive care or anaesthesia, which may affect outcomes. The model of pre‐hospital services, therefore, may be a significant component in future studies and may limit comparability of studies.

Furthermore, training in advanced life support also varies greatly depending on the regional EMS system. While there are some standard certifications (ACLS, PHTLS, etc) many regional EMS systems have their own training programs set up by their medical directors. In addition, requirements for the presence of a certified or advanced life support trained provider at a scene may also differ from region to region. This makes it difficult to compare studies that are conducted in different parts of the world.

Additionally, it is unlikely that a better trained provider provides worse care than a less trained provider as suggested by some studies. Rather, it may be that a better trained provider stays at the scene longer, which then leads to delayed definitive care beyond the so‐called "golden hour" of trauma where it is essential that definitive care is provided as quickly as possible.

Another factor to consider is distance to definitive care. Prehospital providers in more rural locations may benefit more from advanced training so that necessary interventions are not delayed due to travel time. However, in urban settings where distance to a major trauma center is negligible, definitive care can be provided in a more timely fashion when patients are brought to the hospital rapidly by prehospital staff. So skills sets and training may have to be defined and evaluated based on accessibility to major trauma centers.

Authors' conclusions

Implications for practice.

There is no evidence of the effectiveness of advanced life support training for ambulance crews on injury mortality or morbidity.

Implications for research.

There is wide acceptance in high income countries that ALS‐trained ambulance crews are beneficial to major injury victims, spurring its widespread implementation. However, no rigorous evidence supports such policy at this time. A large randomised controlled trial would provide the most reliable evidence of effectiveness of this intervention. Additionally, the use of a step‐wedge design could address some of the ethical concerns such as the perceived lack of equipoise between care by ALS‐trained staff versus that of BLS‐trained staff.

What's new

Date Event Description
21 May 2014 New search has been performed The search for studies has been updated to 16 May 2014. No new studies were identified. The conclusions have not changed.
21 May 2014 New citation required but conclusions have not changed Roger Wong has joined as a co‐author of the review.

History

Protocol first published: Issue 2, 2001
 Review first published: Issue 2, 2001

Date Event Description
24 July 2009 New citation required and conclusions have changed Results from three new studies were included in this update. Conclusions changed from absence of evidence of effectiveness to no evidence to suggest a benefit from this intervention.
The title of the review has changed. The authors of the review have changed. The inclusion criteria of the review has been broadened and now includes interrupted time series studies.
9 July 2008 Amended Converted to new review format.
5 January 2003 New search has been performed New studies sought but none found.

Acknowledgements

We thank Drs. D. Mohan, C. Mock, R. Norton and M. Varghese of the WHO Pre‐hospital Trauma Care Steering Committee for their comments and advice on the review. We thank Mr. R. Wentz and Mrs. K. Blackhall for their help with conducting the searches for intial review. To Frances Bunn, Ian Roberts, Anne‐Maree Kelly, Pablo Perel and Irene Kwan, many thanks for their contribution to the protocol and previous versions of the review. To Deirdre Beecher for conducting the 2014 searches.

Appendices

Appendix 1. Search strategies

Cochrane Injuries Group Specialised Register ((((emerg* or trauma) and (prehospital or pre‐hospital or preclinical or pre‐clinical)) or "life support" or "Primary survey" or "golden hour" or "first aid" or "early management" or EMST or "advanced trauma life support" or ATLS or "advanced life support" or ALS or ("basic life support") or BLS)) AND ( INREGISTER) [REFERENCE] [STANDARD]
 CENTRAL (The Cochrane Library) #1MeSH descriptor: [Emergency Medical Services] explode all trees
 #2MeSH descriptor: [Critical Care] explode all trees
 #3MeSH descriptor: [Emergency Treatment] explode all trees
 #4MeSH descriptor: [Resuscitation] explode all trees
 #5MeSH descriptor: [Emergency Medicine] explode all trees
 #6MeSH descriptor: [First Aid] explode all trees
 #7MeSH descriptor: [Traumatology] explode all trees
 #8(#1 or #2 or #3 or #4 or #5 or #6 or #7)
 #9MeSH descriptor: [Advanced Cardiac Life Support] explode all trees
 #10"Advanced trauma life support" or ATLS:ti,ab,kw (Word variations have been searched)
 #11"Advanced life support" or ALS:ti,ab,kw (Word variations have been searched)
 #12"basic life support" or BLS
 #13(emergency or trauma or critical) near/3 (care or treat*)
 #14(trauma near/3 system*) or (life near/3 support*) or (primary near/3 survey*) or (golden near/3 hour) or (first near/3 aid*):ti,ab,kw (Word variations have been searched)
 #15(early management near/3 trauma) or EMST:ti,ab,kw (Word variations have been searched)
 #16(prehospital or pre‐hospital or preclinical or pre‐clinical) near/3 (care or support or treat*):ti,ab,kw (Word variations have been searched)
 #17(#9 or #10 or #11 or #12 or #13 or #14 or #15 or #16)
 #18MeSH descriptor: [Health Personnel] explode all trees
 #19MeSH descriptor: [Allied Health Personnel] explode all trees
 #20MeSH descriptor: [Medical Staff] explode all trees
 #21MeSH descriptor: [Emergency Medical Technicians] explode all trees
 #22paramedic*:ti,ab,kw (Word variations have been searched)
 #23(emergency or critical or trauma or triage or ambulanc*) near/3 (doctor* or crew* or staff or team*):ti,ab,kw (Word variations have been searched)
 #24(#18 or #19 or #20 or #21 or #22 or #23)
 #25(#8 and #17 and #24)
 Ovid MEDLINE(R), Ovid MEDLINE(R) In‐Process & Other Non‐Indexed Citations, Ovid MEDLINE(R) Daily and Ovid OLDMEDLINE(R) 1.exp Emergency Medical Services/
 2.exp Critical Care/
 3.exp Emergency Treatment/
 4.exp Resuscitation/
 5.exp Emergency Medicine/
 6.exp First Aid/
 7.exp Traumatology/
 8.1 or 2 or 3 or 4 or 5 or 6 or 7
 9.exp Advanced cardiac life support/
 10.((Advanced trauma life support or ATLS) not (ATLS adj3 syndrome*)).ti,ab.
 11.(Advanced life support or ALS).ti,ab.
 12.(basic life support or BLS).ab,ti.
 13.((emergency or trauma or critical) adj3 (care or treat*)).ab,ti.
 14.((trauma adj3 system*) or (life adj3 support*) or (primary adj3 survey*) or (golden adj3 hour) or (first adj3 aid*)).ab,ti.
 15.EMST.ab,ti.
 16.(early management adj3 trauma).ab,ti.
 17.((prehospital or pre‐hospital or preclinical or pre‐clinical) adj3 (care or support or treat*)).ab,ti.
 18.9 or 10 or 11 or 12 or 13 or 14 or 15 or 16 or 17
 19.8 and 18
 20.exp health personnel/
 21.exp allied health personnel/
 22.Medical staff/
 23.paramedic*.ab,ti.
 24.exp Emergency Medical Technicians/
 25.((emergency or critical or trauma or triage or ambulanc*) adj3 (doctor* or crew* or staff or team*)).ab,ti.
 26.20 or 21 or 22 or 23 or 24 or 25
 27.19 and 26
 28.clinical trials as topic.sh.
 29.randomi?ed.ti,ab.
 30.randomized controlled trial.pt.
 31.controlled clinical trial.pt.
 32.(controlled adj3 ("before and after" or trial* or study or studies or evaluat*)).ab,ti.
 33.randomized.ab.
 34.placebo.ti,ab.
 35.((before adj3 after) or (interrupted adj3 time)).ab,ti.
 36.randomly.ab.
 37.trial.ti.
 38.(groups or cohorts).ti,ab.
 39.(observed or observation*).mp.
 40.((compar* or intervention or evaluat*) adj3 (trial* or stud*)).ab,ti.
 41.(random* adj3 allocat*).ab,ti.
 42.exp prospective studies/
 43.exp follow‐up studies/
 44.exp comparative study/
 45.exp cohort studies/
 46.exp evaluation studies/
 47.28 or 29 or 30 or 31 or 32 or 33 or 34 or 35 or 36 or 37 or 38 or 39 or 40 or 41 or 42 or 43 or 44 or 45 or 46
 48.27 and 47
 Embase Classic+Embase (OvidSP) 1.exp Emergency/
 2.exp emergency health service/
 3.exp Emergency Treatment/
 4.exp intensive care/
 5.exp resuscitation/
 6.exp emergency medicine/
 7.exp traumatology/
 8.exp neurotraumatology/
 9.exp First aid/
 10.1 or 2 or 3 or 4 or 5 or 6 or 7 or 8 or 9
 11.((Advanced trauma life support or ATLS) not (ATLS adj3 syndrome*)).ti,ab.
 12.(Advanced life support or ALS).ti,ab.
 13.(basic life support or BLS).ab,ti.
 14.((emergency or trauma or critical) adj3 (care or treat*)).ab,ti.
 15.((trauma adj3 system*) or (life adj3 support*) or (primary adj3 survey*) or (golden adj3 hour) or (first adj3 aid*)).ab,ti.
 16.EMST.ab,ti.
 17.(early management adj3 trauma).ab,ti.
 18.((prehospital or pre‐hospital or preclinical or pre‐clinical) adj3 (care or support or treat*)).ab,ti.
 19.11 or 12 or 13 or 14 or 15 or 16 or 17 or 18
 20.exp medical staff/
 21.exp paramedical personnel/
 22.paramedic*.ab,ti.
 23.((emergency or critical or trauma or triage or ambulanc*) adj3 (doctor* or crew* or staff or team*)).ab,ti.
 24.20 or 21 or 22 or 23
 25.10 and 19 and 24
 26.exp Randomized Controlled Trial/
 27.exp controlled clinical trial/
 28.randomi?ed.ab.
 29.placebo.ab.
 30.exp Clinical Trial/
 31.randomly.ab.
 32.(random* adj3 allocat*).ab,ti.
 33.trial.ti.
 34.(controlled adj3 ("before and after" or trial* or study or studies or evaluat*)).ab,ti.
 35.((before adj3 after) or (interrupted adj3 time)).ab,ti.
 36.(groups or cohorts).ab,ti.
 37.(observ* adj3 (trial* or stud*)).ab,ti.
 38.((compar* or intervention* or evaluat*) adj3 (trial* or stud*)).ab,ti.
 39.exp prospective study/
 40.exp follow up/
 41.exp comparative study/
 42.exp experimental study/
 43.observational study/
 44.exp quasi experimental study/
 45.exp cohort analysis/
 46.exp evaluation research/
 47.exp time series analysis/
 48.or/26‐47
 49.25 and 48

CINAHL Plus (EBSCO Host) S1 TX (Advanced trauma life support or ATLS) NOT (ATLS W3 syndrome)
 S2 TX Advanced life support or ALS
 S3 TX basic life support or BLS
 S4 TI ( (emergency or trauma or critical) ) and TI ( (care or treat*) ) or AB ( (emergency or trauma or critical) ) and AB ( (care or treat*)
 S5 AB ( (trauma AND system*) or (life AND support*) or (primary AND survey*) or (golden AND hour) or (first AND aid*) ) or TI ( (trauma AND system*) or (life AND support*) or (primary AND survey*) or (golden AND hour) or (first AND aid*)
 S6 TX (early management and trauma) OR (EMST)
 S7 AB ( (prehospital or pre‐hospital or preclinical or pre‐clinical) AND (care or support or treat or treatment*) ) or TI ( (prehospital or pre‐hospital or preclinical or pre‐clinical) AND (care or support or treat or treatment*) )
 S8 S1 or S2 or S3 or S4 or S5 or S6 or S7
 S9(MH "Health Personnel+") or (MH "Allied Health Personnel+") or (MH “Emergency Medical Technicians")
 S10paramedic*
 S11(emergency or critical or trauma or triage or ambulanc* ) and (doctor* or crew* or staff or team* )
 S12S9 or S10 or S11
 S13 S8 and S12
 S14 Non‐RCT search strategy saved to server
 S15 S13 and S14

ISI Web of Science: Science Citation Index Expanded (SCI‐EXPANDED); Conference Proceedings Citation Index‐ Science (CPCI‐S)

#20 #19 AND #13
 #19 #18 AND #17
 #18 Topic=(human*)
 #17 #16 OR #15 OR #14
 #16 TS=(((singl* OR doubl* OR trebl* OR tripl*) SAME (blind* OR mask*)))
 #15 TS=((controlled clinical trial OR controlled trial OR clinical trial OR placebo))
 #14 TS=((randomised OR randomized OR randomly OR random order OR random sequence OR random allocation OR randomly allocated OR at random OR randomized controlled trial))
 #13 #12 AND #9
 #12 #11 OR #10
 #11 TS=(((emergency or critical or trauma or triage or ambulanc*) near/3 (doctor* or crew* or staff or team*)))
 #10 TS=(paramedic*)
 #9 #8 OR #7 OR #6 OR #5 OR #4 OR #3 OR #2 OR #1
 #8 TS=(((prehospital or pre‐hospital or preclinical or pre‐clinical) near/3 (care or support or treat*)))
 #7 TS=(("early management" near/3 trauma))
 #6 TS=(EMST)
 #5 TS=(((trauma near/3 system*) or (life near/3 support*) or (primary near/3 survey*) or (golden near/3 hour) or (first near/3 aid*)))
 #4 TS=(((emergency or trauma or critical) near/3 (care or treat*)))
 #3 TS=((basic life support or BLS))
 #2 TS=((Advanced life support or ALS))
 #1 TS=((("Advanced trauma life support" or ATLS) not (ATLS near/3 syndrome*)))

PubMed [www.ncbi.nlm.nih.gov/sites/entrez/] ((((((((((controlled evaluat*[Title/Abstract]) OR controlled trial*[Title/Abstract]) OR controlled study[Title/Abstract]) OR controlled studies[Title/Abstract])) OR (((("controlled before and after"[Title/Abstract])) OR "interrupted time series"[Title/Abstract]) OR cohort*[Title/Abstract])) OR (((("Cohort Studies"[Mesh]) OR "Prospective Studies"[Mesh]) OR "Follow‐Up Studies"[Mesh]) OR "Evaluation Studies"[Publication Type])) OR ((((((("Comparative Study"[Publication Type]) OR "Randomized Controlled Trial"[Publication Type]) OR "Controlled Clinical Trial"[Publication Type])) OR (((((((randomized[Title/Abstract]) OR randomised[Title/Abstract]) OR placebo[Title/Abstract]) OR randomly[Title/Abstract]) OR trial[Title/Abstract]) OR groups[Title/Abstract]) OR group[Title/Abstract])))))) AND (((((((emergency[Title/Abstract] OR critical[Title/Abstract] OR trauma[Title/Abstract] OR triage[Title/Abstract] OR ambulanc*[Title/Abstract]) AND (doctor*[Title/Abstract] OR crew*[Title/Abstract] OR staff[Title/Abstract] OR team*[Title/Abstract]))) OR ((paramedic*[Title/Abstract]) OR para‐medic*[Title/Abstract])) OR (((("Health Personnel"[Mesh]) OR "Allied Health Personnel"[Mesh]) OR "Medical Staff"[Mesh]) OR "Emergency Medical Technicians"[Mesh]))) AND (((((((((((("Advanced Trauma Life Support Care"[Mesh]) OR (((((care[Title/Abstract]) OR support[Title/Abstract]) OR treatment*[Title/Abstract])) AND ((((prehospital[Title/Abstract]) OR pre‐hospital[Title/Abstract]) OR preclinical[Title/Abstract]) OR pre‐clinical[Title/Abstract]))) OR ((((care[Title/Abstract]) OR treat*[Title/Abstract])) AND (((emergency[Title/Abstract]) OR trauma[Title/Abstract]) OR critical[Title/Abstract]))) OR ((golden[Title/Abstract]) AND hour[Title/Abstract])) OR ((primary[Title/Abstract]) AND survey*[Title/Abstract])) OR ((life[Title/Abstract]) AND support*[Title/Abstract])) OR ((trauma[Title/Abstract]) AND system[Title/Abstract])) OR emst[Title/Abstract]) OR ((early management[Title/Abstract]) AND trauma[Title/Abstract])) OR ((((((("advanced trauma life support"[Title/Abstract]) OR atls[Title/Abstract]) OR als[Title/Abstract]) OR bls[Title/Abstract]) OR trauma system[Title/Abstract]) OR basic life support[Title/Abstract]) OR advanced life support[Title/Abstract]))) AND (((((((((((("Emergency Medical Services"[Mesh:noexp]) OR "Critical Care"[Mesh:noexp]) OR "Emergency Treatment"[Mesh:noexp]) OR "Resuscitation"[Mesh]) OR "Emergency Medicine"[Mesh]) OR "First Aid"[Mesh]) OR "Traumatology"[Mesh]) OR "Advanced Cardiac Life Support"[Mesh])) OR ((first[Title/Abstract]) AND aid*[Title/Abstract])) OR (((emergency[Title/Abstract]) OR trauma[Title/Abstract]) OR critical[Title/Abstract])))))) NOT medline[sb]

Characteristics of studies

Characteristics of included studies [ordered by study ID]

Arreola‐Risa 2004.

Methods Controlled before‐and‐after study.
Participants Injured patients from three Mexican cities (Monterrey, San Pedro and Santa Catarina).
Interventions In San Pedro: Basic Trauma Life Support plus Advanced Cardiac Life Support plus a locally‐designed airway course.
In Monterrey: pre‐hospital Trauma Life Support (BTLS equivalent).
In Santa Catarina: no extra training (i.e. control group).
Outcomes Process indicators: use of procedures involving airway management, spinal immobilisation and fluid resuscitations.
Impact indicators: mortality in all injured patients treated by ambulance personnel during the study period and mortality of all injured patients transported by ambulance personnel during the study period (i.e. exclusive of field deaths).
Notes Before and after comparisons were made in 1994 and 1995, respectively, for Monterrey, and 2000 and 2001, respectively, for both San Pedro and Santa Catarina. Data was collected by self‐report on ambulance run‐sheets. No sample size calculations were noted.
Risk of bias
Bias Authors' judgement Support for judgement
Incomplete outcome data (attrition bias) 
 All outcomes Unclear risk It is unclear how many ambulance crews or personnel did not participate in the study or if there was attrition of trained crew members during the study time period and if this influenced outcomes in any way. Authors also do not report if mortality data was not collected or missing for any eligible patients who were entered in the study.
Selective reporting (reporting bias) High risk Deaths in one city were assessed differently compared to those in the other two cities. In Monterrey, deaths in the field or en route to the Emergency Department were captured, but not those that occurred later in the Emergency Department stay or in the hospital. In San Pedro and Santa Catarina, hospital records were used to ascertain deaths, especially for patients at high risk of mortality.
Other bias Unclear risk Authors do not report if the ambulance crews in the cities were aware of what interventions were being provided by the other. It appears that no blinding of this information occurred.

Nicholl 1998.

Methods Randomised controlled trial (of dispatch of paramedics and technicians by opening sealed numbered envelopes when a potentially eligible emergency call was received).
 Decisions about whether to include a patient were made after randomisation, according to whether the inclusion criteria was met.
Participants 16 trauma patients of all ages, hospitalised due to road traffic accidents, falls,
 work/chemical/sport accidents, self‐harm and drowning.
 Inclusion and exclusion criteria retrospectively applied:
 Included:
 Length of hospital 1. stay =/> 3 days,
 2. Admissions to ICU/HDU,
 Deaths between ambulance arrival on scene and arrival at
 hospital.
 3.
 Transfer to another hospital or hospital's ICU/HDU with
 stay =/> 3 days,
 4.
 5. Re‐admission within 2 days of the incident,
 6. All deaths within 6 months of the incident.
 Excluded:
 1. Poisonings,
 2. Transported by helicopter,
 3. Attended by doctors on scene,
 4. Deaths before ambulance arrival,
 5. Superficial skin injuries and burns,
 6. Simple fracture of femur in patients > 65 years old,
 7. Simple spinal strain with no fracture,
 8. Patients involved in 'major incidents'.
Interventions Pre‐hospital trauma care provided by ALS trained
 paramedic (n = 8).
 Pre‐hospital trauma care provided by BLS trained
 emergency technicians (n = 8).
Outcomes 1. process of care,
 2. morbidity as measured by general health perception and quality of life
 in a 6‐month follow‐up postal questionnaire (SF‐36),
 3. death within 6 months of the incident.
Notes Poor protocol compliance.
 Mortality and morbidity data of these 16 cases were added to
 main non‐randomised cohort for analysis.
Risk of bias
Bias Authors' judgement Support for judgement
Allocation concealment (selection bias) Low risk Adequate ‐‐ sealed numbered envelopes.
Incomplete outcome data (attrition bias) 
 All outcomes Unclear risk ‐
Selective reporting (reporting bias) Unclear risk ‐
Other bias Unclear risk ‐

Stiell 2008.

Methods Uncontrolled before‐and‐after study.
Participants Injured patients over 16 years of age with an injury severity score greater than 12, all of whom were transported by land ambulance and treated at one of the 13 lead trauma hospitals in Ontario province.
Interventions Two phases: basic life‐support and then advanced life‐support training and interventions were conducted, each 36 months in duration. ALS training consisted of a standardised national curriculum on advanced life‐support and clinical training programs. Training included use of endotracheal intubation, intravenous line placement and use of intravenous medications and fluids.
Outcomes The primary outcome was survival to hospital discharge (alive, or being transferred to a long‐term care facility) and was obtained from hospital records. Additionally, disease‐specific quality of life in survivors was measured with the 7‐level functional independence measure at discharge and six months.
Notes Non‐randomised. No contemporaneous controls.
Risk of bias
Bias Authors' judgement Support for judgement
Incomplete outcome data (attrition bias) 
 All outcomes Unclear risk Authors do not report attrition in ambulance personnel during the study time period and if this influenced outcomes in any way.
Selective reporting (reporting bias) Low risk Outcomes were collected from hospital records from all settings and analyses take into account missing data or patients who became lost to follow‐up.
Other bias Low risk Authors conducted and reported a detailed analysis of potential confounders and other explanations for the study's results although the study design increases risk of bias.

Characteristics of excluded studies [ordered by study ID]

Study Reason for exclusion
Boyle 2009 Retrospective review of prehospital errors associated with road traffic fatalities over a 10 year period. Increase in prehospital error rates coincided with introduction of ALS for paramedics and the state trauma system in Victoria. Interesting, but did not fit previously established study design criteria.
Eckstein 2000 A prospective cohort study of injured patients who received either bag‐valve‐mask or endotracheal intubation for breathing assistance in the pre‐hospital setting, did not fit the previously established study design criteria.
Johansson 2012 A population‐based observational study of 2380 injured patients. Prehospital records were linked to hospital discharge records or cause of death records and correlated with PHTLS training and education leave of ambulance crews. PHTLS training was associated with a non‐precise (non‐significant) reduction in mortality. Study did not fit previously established study design criteria.
Lee 2003 A retrospective review of 2010 severe blunt trauma patients with or without severe head injury, did not fit the previously established study design criteria.
Liberman 2003 A prospective cohort study, did not fit the previously established study design criteria.
Messick 1992 A descriptive study, did not fit the previously established study design criteria.
Ryynanen 2010 A systematic review, not analysis of primary data, did not fit the previously established study design criteria.
Sampalis 1993 A case‐control study, did not fit previously established inclusion criteria.
Sukamaran 2005 A cohort study comparing the care provided by paramedics with ALS training and technicians with BLS training and outcomes of injury victims treated by each group. Did not fit the previously established inclusion criteria.

Differences between protocol and review

The protocol was modified to include interrupted time series studies since this design is often used to test the effectiveness and impact of pre‐hospital interventions based on the ethical considerations influencing any study of pre‐hospital care.

Contributions of authors

For the protocol, and review versions through the 2008 update: DS helped to design the protocol, examined search results, applied inclusion criteria and wrote the review. IK helped design the protocol, examined search results, applied inclusion criteria, obtained papers, extracted data, contacted authors and helped to write the review. AMK applied inclusion criteria, extracted data and helped to write the review. IR and FB commented on the protocol and helped to write the review.

For the 2009 update: SJ examined search results, obtained papers, applied inclusion criteria, extracted data, contacted authors and edited the review.

For the 2014 update: SJ and RW examined search results, obtained papers, applied inclusion criteria, and edited the review.

Sources of support

Internal sources

  • Institute of Child Health, University of London, UK.

External sources

  • Global Programme on Evidence of Health Policy (GPE), World Health Organization, Switzerland.

  • Virginia Commonwealth University Medical Center, Department of Surgery, USA.

Declarations of interest

SJ: None known.

DS: None known.

RW: None known.

New search for studies and content updated (no change to conclusions)

References

References to studies included in this review

Arreola‐Risa 2004 {published data only}

  1. Arreola‐Risa C, Mock C, Herrera‐Escamilla A, Contreras I, Vargas J. Cost‐effectiveness and benefit of alternatives to improve training for prehospital trauma care in Mexico. Prehospital and Disaster Medicine 2004;19(4):318‐25. [DOI] [PubMed] [Google Scholar]

Nicholl 1998 {published data only}

  1. Nicholl J, Hughes S, Dixon S, Turner J, Yates D. The costs and benefits of paramedic skills in pre‐hospital trauma care. Health Technology Assessment 1998;2(17):1‐72. [PubMed] [Google Scholar]

Stiell 2008 {published data only}

  1. Stiell I, Nesbitt L, Pickett W, Munkley D, Spaite D, Banek J, et al. The OPALS Major Trauma Study: impact of advanced life‐support on survival and morbidity. Canadian Medical Association Journal 2008;178(9):1141‐52. [DOI] [PMC free article] [PubMed] [Google Scholar]

References to studies excluded from this review

Boyle 2009 {published data only}

  1. Boyle MJ. Comparison overview of prehospital errors involving road traffic fatalities in Victoria, Australia. Prehospital and Disaster Medicine 2009;24(3):254‐61. [DOI] [PubMed] [Google Scholar]

Eckstein 2000 {published data only}

  1. Eckstein M, Chan L, Schneir A, Palmer R. Effect of prehospital advanced life support on outcomes of major trauma patients. Journal of Trauma 2000;48(4):643‐8. [DOI] [PubMed] [Google Scholar]

Johansson 2012 {published data only}

  1. Johansson J, Blomberg H, Svennblad B, Wernroth L, Melhus H, Byberg L, et al. Prehospital Trauma Life Support (PHTLS) training of ambulance caregivers and impact on survival of trauma victims. Resuscitation 2012;83(10):1259‐64. [DOI] [PubMed] [Google Scholar]

Lee 2003 {published data only}

  1. Lee A, Garner A, Fearnside M, Harrison K. Level of prehospital care and risk of mortality in patients with and without severe blunt head injury. Injury 2003;11:815‐9. [DOI] [PubMed] [Google Scholar]

Liberman 2003 {published data only}

  1. Liberman M, Mulder D, Lavoie A, Denis R, Sampalis J. Multicenter Canadian study of prehospital trauma care. Annals of Surgery 2004;237(2):153‐60. [DOI] [PMC free article] [PubMed] [Google Scholar]

Messick 1992 {published data only}

  1. Messick W, Rutledge R, Meyer A. The association of advanced life support training and decreased per capita trauma death rates: an analysis of12,417 trauma deaths. Journal of Trauma 1992;33(6):850‐5. [DOI] [PubMed] [Google Scholar]

Ryynanen 2010 {published data only}

  1. Ryynanen OP, Iirola T, Reitala J, Palve H, Malmivaara A. Is advanced life support better than basic life support in prehospital care? A systematic review. Scandinavian Journal of Trauma, Resuscitation and Emergency Medicine 2010;18:62. [DOI] [PMC free article] [PubMed] [Google Scholar]

Sampalis 1993 {published data only}

  1. Sampalis JS, Lavoie A, Williams JI, Mulder DS, Kalina M. Impact of on‐site care, prehospital time, and level of in‐hospital care on survival in severely injured patients. Journal of Trauma 1993;34(2):252‐61. [DOI] [PubMed] [Google Scholar]

Sukamaran 2005 {published data only}

  1. Sukumaran S, Henry JM, Beard D, Lawrenson R, Gordon MWG, O’Donnell JJ, et al. Prehospital trauma management: a national study of paramedic activities. Emergency Medicine Journal 2005;22:60‐3. [DOI] [PMC free article] [PubMed] [Google Scholar]

Additional references

AACE 2013

  1. Association of Ambulance Chief Executives. UK Ambulance Services Clinical Practice Guidelines. Joint Royal Colleges Liaison Committee 2013. [http://aaceguidelines.co.uk/] [Google Scholar]

Ali 1993

  1. Ali J, Adam R, Butler AK, Chang H, Howard M, Gonsalves D, et al. Trauma outcome improves following the advanced trauma life support program in a developing country. Journal of Trauma 1993;34:890‐9. [DOI] [PubMed] [Google Scholar]

Areola‐Risa 2000

  1. Areola‐Risa C, Mock CN, Lojero‐Wheatly L, Cruz O, Garcia C, Canavati‐Ayub F, et al. Low cost improvements in prehospital trauma care in a Latin American city. Journal of Trauma 2000;48:119‐24. [DOI] [PubMed] [Google Scholar]

Berger 1996

  1. Berger LR, Mohan D. Injury control: a global view. Oxford: Oxford University Press, 1996. [Google Scholar]

Berlin 1997

  1. Berlin JA. Does blinding of readers affect the results of meta‐analyses?. Lancet 1997;350:185‐6. [DOI] [PubMed] [Google Scholar]

Cales 1984

  1. Cales RH. Trauma mortality in Orange County: The effects of implementation of a regional trauma system. Annals of Emergency Medicine 1984;13:1‐8. [DOI] [PubMed] [Google Scholar]

Calicott 1980

  1. Calicott PE, Hughes I. Training in trauma advanced life support. Journal of the American Medical Association 1998;243:1156. [Google Scholar]

DoH 2011

  1. Department of Health. Transforming NHS ambulance services. National Audit Office 2011; Vol. June. [http://www.nao.org.uk/wp‐content/uploads/2011/06/n10121086.pdf]

Gwatkin 1997

  1. Gwatkin DR, Heuveline P. Improving the health of the world's poor. Communicable diseases among young people remain central. BMJ 1997;315:497. [DOI] [PMC free article] [PubMed] [Google Scholar]

Hauswald 1997

  1. Hauswald M, Yeoh E. Designing a prehospital system for a developing country: estimated costs and benefits. American Journal of Emergency Medicine 1997;15:600‐3. [DOI] [PubMed] [Google Scholar]

Higgins 2011

  1. Higgins JPT, Green S (editors). Cochrane Handbook for Systematic Reviews of Interventions Version 5.1.0 [updated March 2011]. The Cochrane Collaboration, 2011. Available from www.cochrane‐handbook.org.

Jayaraman 2014

  1. Jayaraman S, Sethi D, Chinnock P, Wong R. Advanced trauma life support training for hospital staff. Cochrane Database of Systematic Reviews 2014, Issue 8. [DOI: 10.1002/14651858.CD004173.pub4] [DOI] [PMC free article] [PubMed] [Google Scholar]

JRCALC 2010

  1. Joint Royal Colleges Ambulance Liaison Committee. Resuscitation Supplement. Warwick: National Coordinating Centre for the UK Ambulance Services Clinical Practice Guidelines, 2010. [http://www2.warwick.ac.uk/fac/med/research/hsri/emergencycare/prehospitalcare/jrcalcstakeholderwebsite/clinicalpracticeupdates/resuscitation_supplement_2010_version_2_‐_24th_august_2011.pdf] [Google Scholar]

Kirsch 1998

  1. Kirsch TD. Emergency medicine around the world. Annals of Emergency Medicine 1998;32:237‐8. [DOI] [PubMed] [Google Scholar]

Lecky 2000

  1. Lecky F, Woodford M, Yates DW. Trends in trauma care in England and Wales 1989‐97. Lancet 2000;355:1771‐5. [DOI] [PubMed] [Google Scholar]

Lopez 2006

  1. Lopez AD, Mathers CD, Ezzati M, Jamison DT, Murray CJ. Global and regional burden of disease and risk factors, 2001: systematic analysis of population health data. The Lancet 2006;367(9524):1747‐57. [DOI] [PubMed] [Google Scholar]

Mathers 2006

  1. Mathers CD, Loncar D. Projections of global mortality and burden of disease from 2002 to 2030. PLoS Medicine 2006;3(11):e442. [DOI] [PMC free article] [PubMed] [Google Scholar]

Murray 1997a

  1. Murray CJL, Lopez AD. Mortality by cause for the eight regions of the world: Global Burden of Disease Study. Lancet 1997;349:1269‐76. [DOI] [PubMed] [Google Scholar]

Murray 1997b

  1. Murray CJL, Lopez AD. Global mortality, disability, and the contribution of risk factors: Global Burden of Disease Study. Lancet 1997;349:1436‐42. [DOI] [PubMed] [Google Scholar]

Murray 1997c

  1. Murray CJL, Lopez AD. Alternative projections of mortality and disability by cause 1990‐2020: Global Burden of Disease Study. Lancet 1997;349:1498‐504. [DOI] [PubMed] [Google Scholar]

Reines 1998

  1. Reines HD, Bartlett RL, Chudy NE, Kiragu KR, McKnew M. Is advanced life support appropriate for victims of motor vehicle accidents: the South Carolina highway trauma project. Journal of Trauma 1998;28:563‐70. [DOI] [PubMed] [Google Scholar]

Roberts 1996

  1. Roberts I, Cambell F, Hollis SS, Yates D. Reducing accident death rates in children and young adults: the contribution of hospital care. BMJ 1996;313:1239‐41. [DOI] [PMC free article] [PubMed] [Google Scholar]

Sethi 2000

  1. Sethi D, Aljunid S, Sulong SB, Zwi A. Injury care in low‐and middle‐income countries: identifying potential for change. Injury Control & Safety Promotion 2000;7:153‐64. [Google Scholar]

Sklar 1988

  1. Sklar DP. Emergency medicine and the developing world. American Journal of Emergency Medicine 1988;6:390‐3. [DOI] [PubMed] [Google Scholar]

VanRooyen 1999

  1. VanRooyen MJ, Thomas TL, Clem KJ. International emergency medical services: assessment of developing prehospital systems abroad. Journal of Emergency Medicine 1999;17:691‐6. [DOI] [PubMed] [Google Scholar]